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Table 1 <br />Potential Efficiencies by Irrigation Systems <br />Irrigation System Type Potential <br />Efficienc Irrigation System Type Potential <br />Efficienc <br />Borders (%) Flood Irri ag tion (%) <br />Level or Basin 90 Controlled 60 <br />Graded 80 Uncontrolled 50 <br />Guide 70 Contour Ditch 60 <br />Contour -level Sprinkler <br />Field Crop 70 Big gun or boom 60 <br />Rice 80 Hand or wheel line 70 <br />Border Ditch 60 Solid set (above canopy) 75 <br />Furrow Solid set (below canopy) 80 <br />Level or Basin 90 Center-pivot 80 <br />Graded 75 Center-pivot (LEPA) 85 <br />Contour 75 Trickle <br />Corrugations 75 Point Source 90 <br />Surge 85 Spray emitters 85 <br />Sub-irrigated 75 Continuous tape 90 <br />Source: Klamm and Brenner (1995) <br />Recommendations -Maximum Application Efficiencies <br />The StateCU model uses maximum application efficiencies to estimate the amount of <br />irrigation water delivered to the farm that is available to meet crop consumptive use <br />demands. The flood irrigated and sprinkler irrigated acreage under each ditch system, by <br />year, and maximum flood and sprinkler efficiencies are input to the StateCU model. The <br />actual application efficiency is calculated within the model based on historic water supply <br />and maybe considerably less than the input maximum application efficiency. <br />Although actual application efficiency can vary with crop type and soil type, a consistent <br />maximum application efficiency is recommended throughout the basin based on <br />irrigation method. Table 2 shows the recommended maximum application efficiencies <br />for use in the consumptive use analysis. These efficiencies are consistent with published <br />data reviewed for Task 56 including user information and efficiencies published in <br />engineering reports supporting water court applications and adjudications. <br />Table 2 <br />Recommended Maximum Application Efficiencies <br /> <br />Flood Irrigation Sprinkler <br />Irrigation <br />60 % 80 <br />Comments and Concerns <br />The recommended conveyance efficiencies are appropriate for use in analyses performed <br />as part of the SPDSS project. However, ditch loss data were only available for large <br />ditch systems. In addition, the GIS canal coverage may not include all the ditch systems, <br />and some ditches may include main canal plus laterals while others may only include the <br />Page 4 of 5 <br />